1. Field of the Invention
The present invention relates to splint type devices, and more particularly, to a finger splint for correction of marked hyperextension at a finger distal joint.
2. Description of the Prior Art
Written communication skills are extremely important in modern society and, in particular, during the educational process from grammar school through college. Some students who have been found to have learning disabilities also have illegible handwriting. Most remedial programs designed to solve handwriting problems for students have considered that the ability of the student to grasp the writing instrument and to maintain an acceptable grasp while writing are important elements. In the past, such programs have assumed that this elementary ability is present in the subject and have concentrated on the handwriting instrument, the paper, the position of the hand, and the formation of the letters. However, one of the co-inventors of the present invention, an occupational therapist, in observing learning disability students in Ormond Beach, Fla., discovered that many such students with poor handwriting do not demonstrate an acceptable grasp on the writing instrument and have difficulty in maintaining their grasp for even a short period of time. Further investigation of the joint posture of the digits directly involved in handwriting in these students revealed that one or more of the three interphalangeal joints used in grasping would bend back into marked hyperextension when pressure was applied to the writing instrument. Such marked hyperextension prevents the student from assuming the normal grasp and control necessary for handwriting. The therapist screened 80 problem students in three schools and found 33 of these students who exhibited marked hyperextension at the distal joints of thumbs and fingers. As discussed in Hand Pain and Impairment, Cailliet, Rene; Philadelphia; F. A. David Company, 1975, such marked hyperextension is considered an abnormality of the distal joint.
As a result of these observations, the therapist set up matched pairs of students as experimental and control groups to develop and evaluate a practical device for correcting the noted physical abnormality. The therapist determined that a simple finger splint having a carefully selected shape, size, and tension can provide support for fingers and thumbs having the noted hyperextension of the distal joint. An in-depth survey of medical literature and authorities on finger joints has failed to reveal either prior identification of this problem in handwriting or suitable appliances for correction of the problem. Similarly, investigation into the literature and authorities on penmanship and correction of unsatisfactory penmanship yielded a void in this area.
The only known commercially available appliance suitable for fingers is the "Spling" adjustable finger flexion orthosis manufactured by LBM Hand Rehab Products, Long Beach, Calif. This appliance is a splint designed for finger joints other than the distal joint and were found unsuitable for the present application. Thus, there exists a need for a small, light weight, flexible splint usable with the distal joints of the fingers and thumb to assist persons with the noted hyperextension to improve tasks involving the prehensile grasp.